Well, it was acting up again today on the way to get my son from daycare. Turned it off, walked inside, restarted about 5 minutes later and it ran fine all the way home. No codes.

FPDM might be next on the list.

 

well if it makes you feel better about changing it (& I was clueless when it happened to me) & I drive commercially!!! mine for @ least 6 months ++ would sometimes: I would shut it off go into store come out & it would crank & no start...(quite a few times this happened.......I developed a sequence where along side of the road with limited tools I would remove the + battery post & then that connection 2 '' away then remove the red + cable going into the fuse box on top of rad.....Put it all back together & it would start!!!
So I figured it was a power issue right....WRONG.....Then one day on a trip I kinda felt my motor was a little short on power as in no same get up & go....Drove it to my mechanic & he changed out the FPDM said I was lucky it didn't leave me on the side of the road !!!!!! IT SURE TRIED but it started every time I checked/cleaned those dam terminals.....Normal power & smoothness was now back......No problems ever since.......Good Luck!!

 

TO really throw a wrench into the works, I recently had a car that wouldn’t start because of a loose battery terminal INSIDE the battery. Anything’s possible... but FPDM should be top priority. My truck was on its third at 150k, stalled 150 miles from home but restarted. Case was corroded but intact. I suspect internal Dorman failure.

 

Update on this:

1) still haven’t checked/ replaced the FPDM.
2) the truck is still acting up.
3) still no fault codes
4) I’ve been using my SCT X4 to monitor engine load, fuel pressure, trans temp, and fuel pump duty cycle.

While the truck is acting up, even if I floor it, engine load only maxes out at 66%, trans temp never crests 185*, fuel pump duty cycle never dips below 23%, and fuel pressure remains steady at between 39-54 psi.

I did notice last time it decided to come back to life while mashing the gas to merge into traffic, the truck basically completely stopped responding to accelerator input for about 1 second and then took off as I would expect. Tonight it came back to life in the rain mid-corner. It got a little... tail happy for a moment.

I can’t find a way to monitor A/F ratio on the X4 out of the box unless its called something else.

 

Now, it seems like a TPS/TB issue. Mine had all sorts of issues until I replaced them: odd surges in power with my foot off the pedal, stalling at lights, no power followed by full power...

 

You just did both at the same time?

 

Brand new Ford TB came with the updated TPS. I’d also gotten the occasional code for it, but only when I attempted a tune with the edge. Turns out I’d get the code with the Edge after replacing the TB too, but never had any more driveabilty issues.

 

Good to know! Thanks.

 

just saw your last post when I replaced my FPDM there was no codes just that last week or so I realized it was lacking get up & go...
Mine I figured was acting up from the summer of 2018 when it wouldn't start (8-10 times @ least) till spring of 2019...

 

2007 F150 FX4 90,000miles I have a similar issue- no codes-truck feels like I'm pulling a heavy trailer almost the whole time -the tranny shifts fine and all until overdrive, it kind of just drops in and sluggish/like shifting from 3rd to 5th almost/not quite as bad but it just drops off, I can push in to the kick down and it gets up and go's
replaced:
Timing/phasers/VCT/TB/MAF/Coils/Plugs/ And had the Cats checked- only thing I haven't tried is The FPDM.

Truck runs and idles perfect(well as good as these modular motors get)- had a slight surge/delay in acceleration (I would ease in to throttle and then it would surge after a second or two) this went away after Replacing TB/MAF